物理学报Issue(13)：1-7,7.DOI:10.7498/aps.64.137501
金属离子掺杂对CuO基纳米复合材料的交换偏置调控∗
Exchange bias tuning of metal ions dop ed in CuO nano comp osites
摘要
Abstract
In this paper, the nanocomposites are synthesized by the non-equal precipitation method to study the effect of the metal ions doped in antiferromagnetic matrix on the exchange bias. XRD patterns and SEM images reveal that the as-synthesized CuO nanocomposites have uniform size (∼ 80 nm), and the ferrimagnetic particles MFe2O4 (M = Cu, Ni) are embedded in the antiferromagnetic (AFM) CuO matrix by doping of magnetic metal ions Ni and Fe. And the ferrimagnetic phase MFe2O4 (M =Cu, Ni) is formed through the addition of a small amount of Fe that reacts with Cu and Ni ions. Effects of different doping amount of Ni on exchange bias are different. A small doping amount of Ni can induce magnetic disorder at the interface of both phases, then the spin-glass-like phase may be formed. The spin-glass-like phases enhance the pinning effect on the magnetic moments of ferrimagnetic phase. Meanwhile, during field cooling process the antiferromagnetic phase splits into domains, which are aligned either with cooling field or in the original antiferromagnetic configuration. The domain wall serves as pinning sites for the magnetic moments of ferromagnetic phase, and the exchange bias effect is increased. The AFM NiO grains with high anisotropic energy are generated, this also increases the exchange bias effect when continuous doping of Ni ions. In the process of field cooling (FC), upward shift occurs in all hysteresis loops, which is perpendicular to the exchange bias. As x=0.08 (x is the concentration of Ni) the perpendicular displacement is 3.6%, this behavior also proves that under FC measurements, the spin-glass-like phase can be formed between the antiferromagnetic nanopaticles. It is the magnetic exchange coupling at the interface between the ferrimagnetic phase and the spin-glass-like phase that result in an upward shift in the entire measurement range. The plot of M versus T under zero field cooling (ZFC) and field cooling (FC) indicates that the exchange bias effect in these composites is ascribed to the exchange coupling at the interface between the ferrimagnetic particles and the spin-glass-like phase. With continuous introduction of magnetic Ni ions, the exchange bias field first increases slowly, then at x=0.08 it increases sharply. The existence of AFM NiO with high anisotropic energy and the domain structure in AFM matrix are the causes of the result.关键词
掺杂/交换偏置/亚铁磁/反铁磁Key words
doping/exchange bias/ferrimagnetic/antiferromagnetic引用本文复制引用
刘奎立,周思华,陈松岭..金属离子掺杂对CuO基纳米复合材料的交换偏置调控∗[J].物理学报,2015,(13):1-7,7.基金项目
河南省科技厅基础前沿技术研究计划项目(批准号:122300410168)和河南省教育厅高校青年骨干教师项目(批准号:2012GGJS-181)资助的课题.* Project supported by the Henan Provincial Research Foundation for Basic Research, China (Grant No.122300410168) and the Young Core Instructor Foundation from the Education Commission of Henan Province, China (Grant No.2012GGJS-181) （批准号:122300410168）
